Formboard support



J. M. ANDERSON FORMBOARD SUPPORT Filed Sept. 17, 1957 Aug. 12, 1958 R N w w M m w E v n lm m m fi Q mm mm w Y J 4% 1 A g QM M 7 M v m 4 A J 0% QM Y mm hm IA\|| WW 5 4 m g VA, 474 J II II QM E a! 2,846,750 Patented Aug. 12, 1958 FORMBOARD SUPPGRT James M. Anderson, Miami, Fla. Application September 17, 1957, Serial No. 684,523

6 Claims. (Cl. 25131.S)

This invention relates to temporary supports and, more particularly, an extensible beam for use as a formboard support during the pouring and curing of light-weight concrete slabs providing light-weight roof deck, carport, and breezeway roofing and like surfaces.

Extensible beam supports for use as temporary formcourse, be used in the construction of light-weight concrete roof decks and roof structures of the character mentioned above, they are highly inefiicient in such usage due (1) to their unduly heavy weight and bulk which renders them diflicult to. secure in position, cumbersome and expensive to transport from job to job and to handle in putting them to the intended use, and (2) to their complex construction and fragile stops necessitating costly maintenance service in spite ofthe exercise of proper erection and disassembly techniques.

Examples of previously proposed extensible beam supports are found in United States Letters Patent 2,3 86,161 issued October 2, 1945, to A. H. Hawes and 2,403,853 issued July 9, 1946, to B. W. Fromson and Danish Letters Patent 72,262 issued March 12, 1951, to H. K. B. Petersen.

The primary object of this invention, therefore, is to provide a simplified, lightweight, telescopically adjustable beam support member for use as a temporary formboard support in lightweight concrete construction work and he like.

Another object of this invention is to provide an adjustable beam support member, which can be economically fabricated from rugged, inexpensive conventional 90 angle iron stock through-use of simple welding operations and without the need of any machinery operations or use of expensive skilled labor or shop work.

A still further object of the present invention is to provide an extensible formboard support of simple construction for temporary use in light-weight concrete roof deck and like construction which can be satisfactorily locked in a desired extended position by use of simple wooden wedges which, upon conclusion of the temporary need for such supports, can be quickly removed by a hammer blow of an unskilled workman passing beneath the formboard supported cured concrete slab without any possibility of damaging the extensible support and thus necessitating maintenance operations with its incident costs.

Other objects of the invention will appear from the following description and appended claims when read in conjunction with the accompanying drawings wherein:

Figure 1 is a top plan view of the telescopically adjustable support beam of this invention in spanning position between adjacent roof purlins supporting a formboard'with certain parts in phantom lines for clarity of illustration;

Figure 2 is a front elevation of the telescopically adjustable beam of Figure 1 showing the roof truss support for the purlins in the'background;

Figure 3 is a view taken along the line 3-3 of Figure 1 with the formboard, purlins and roof truss support omitted for purposes of clarity; and

Figure 4 is a View similar to Figure 3 taken along the line 4-4 of Figure 1.

Referring now more specifically to the drawings, there is illustrated in Figures 1 and 2 an adjustable, telescopically expansible and contractible temporary support beam of the present invention indicated generally by numeral and comprising a pair of interfitting elongated angle members 12 and 14, respectively, formed from conventional 90 angle iron stock. Angle member 12 provides flange 16 which forms a horizontal supporting surface for a concrete formboard 15 shown broken away in Figure 1 and in section in Figure 2. The other flange 18 of angle member 12 provides a depending slide surface which, together with the undersurface of flange 16, slidingly engages the outer wall surfaces of angle member 14. As clearly appears from an inspection of Figures 3 and 4 of the drawings angle member 14 is of smaller size than angle member 12 and nests within the dihedral angle formed by flanges 16 and 18 of angle member 12. The flange 20 of member 14 forms a formboard support surface, at least that. portion which protrudes beyond the end of member 12, although its top surface lies in the plane of .the inner surface of flange 15 and flange 22 the outside surface of which lies in the plane of the inside surface of flange 18. The nature of the work for which the beam of this invention is designed does not require a continuous formboard support surface so the diiference in level of the support surfaces of flanges 16 and 20 is'of no consequence. The outer ends of flanges 18 and 22, as indicated by numeral 25, terminate short of the adjacent ends of flanges 16 and 20 which provide opposed end support surfaces 24 and 26 at opposite ends ofthe beam 10 in order that it may be supported in spanning relation between purlines 23 as best shown in Figure-2. While purlines 28 mayassume various forms, they are here illustrated as I beams, the opposite ends'of which are rafters 29 illustrated in Figure 2 as flanged I beam or channelmembers although they also may take any other suitable form.

Angle members 12 and 14 are held in nested sliding relation by spaced guide straps 30 secured by welds 32, as shown in Figure 3, to the edges of flanges 16 and 18 or angle member 12 which protrude beyond the corresponding edges of'the mating flanges 20 and 22 of angle member 14. Preferably guide straps 30 are cut'from conventional angle stock of suitable size. It, of course, will be appreciated that guide straps 30 could be replaced by generally U-shaped straps welded to the edges of member 12 at spaced intervals along its length with one leg passing inwardly around the respective edges of inner member 14 without departing from the spirit of the present invention.

To determine the maximum and minimum length of beam 10 and prevent angle members 12 and 14 from becoming disengaged, a stop member 34 of 90 angle stock is Welded to the inside surface of angle member 14 between guide straps 30. The outer edges of stop 34 extend sufficiently beyond the corresponding edges of member 14 to abut against the opposed inner edges of guide straps 30 and thus limit telescopic movement of the beam members in an inner and an outer direction. Although stop member 34 is illustrated as being of 90 angle stock, it may also be in the form of a square or round tube section welded in the angle of the angle service without any maintenance cost.

member 14. Any of such stops would facilitate removal of the formboard support after the concrete has set. This may be accomplished-by use of a pole or any suitable long handled device pushed or banged against the stop from the floor below to telescopically shorten the formboard support to a point where it is no longer sup-' ported by purlines 28.

When beam 10 is mounted as shown in Figure 2, it may be conveniently locked against accidental telescopic movement at the desired length by driving a Wedge 36, preferably of wood, between a guide strap 30 and angle member 14 as best shown in Figure 2. Wedges 36 may be quickly and conveniently made at the job location from suitable scrap lumber and may be quickly removed by a hammer blow on the smaller end when dismantling of the formboard structure is desired. Being formed from scrap lumber, these wedges are quite inexpensive though extremely effective and need not be salvaged for reuse.

From the foregoing description and drawings, it is readily apparent that all of the components making up the adjustably telescopicaly expansible and contra-ctable temporary support beams 10 of this invention may be produced economically and provide an extremely simple, yet rugged construction that will provide long and eflicient It will also be appreciated that suitable choice of the size, thickness and nature of the material employed in angle members 12 and 14 assures a support beam of minimum weight that can be most conveniently transported, installed and dismantled.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A longitudinally adjustable beam for use as a temporary formboard support in casting and curing light concrete slabs comprising a pair of nested elongated angle members the flanges of which are disposed with their respective outer and inner surfaces in sliding surface engagement; guide means secured to one of said members and having portions in overlying relation to the other member for maintaining said angle members in sliding assembled relation for adjustable telescopic movement; and stop means carried by one member for engaging the other member and limiting said telescopic movement in an inner and an outer direction.

2. A telescopic support beam comprising an outer elongated angle member; an inner elongated angle memher disposed in nested sliding engagement With said outer elongated angle member; guide straps secured in longitudinal spaced relation to-the edges of said outer angle member and having portions in overlying relation to said inner member for holding said angle members in sliding assembled relation; a stop element secured to said inner angle member in a position between said guide straps and having opposed portions adapted to engage a respective one of a pair of said guide straps to limit telescopic movement of said angle members in relation to each other at an outermost and an innermost position.

3. A "longitudinally adjustable support beam for use as a temporary support in casting and curing light concrete slabs comprising a pair of elongated angle members having respective flanges which intersect at substantially right angles disposed with the outer flange surfaces of one of said angle members in'sliding surface engagement with the inner flange surfaces of the other of said members; spaced guide straps of angle configuration in cross-section having its side edges secured to the op posing edges of the flanges of the other angle member, said guide straps being adapted to retain said angle members in sliding assembled relation for adjustable telescopic movement; and a stop member secured to an inner surface of said one angle member and disposed to move between spaced guide straps, said stop member having at least one outer end disposed to respectively abut said spaced guide straps for limiting relative telescopic movement of said angle members in opposite directions.

4. The support beam of claim 3 in which the outer respective opposite ends of a respective pair of engaged flanges protrudes axially beyond the adjacent ends of References Cited in the file of this patent UNITED STATES PATENTS 634,671 Perret Oct. 10, 1899 949,093 Sherwood Feb. 15, 1910 2,239,315 Vigier Apr. 22, 1941 2,711,806 Smith June 28, 1955 FOREIGN PATENTS 879 Great Britain July 30, 1914 479,029 Great Britain Jan. 25, 1938 

